Food that "burned" my throat

(I wasn't sure what other forum to post this to, hopefully this is appropriate here)

Yesterday, I ate lunch at a Round Table Pizza where I put crushed red pepper on my pizza. I ALWAYS do this. The "hotness" doesn't really bother me, I can usually tolerate Habaneros anyway. I am wondering if there wasn't some foreign substance in that packet of pepper, however. Of all the hot foods I've eaten over the years, this was a completely different sensation.

I barely took one bite of pizza and was immediately in pain. Whatever it was made my throat feel like it was on fire, and I was in tears for about 15 minutes. The burning sensation in my lower throat lasted for 2+ hours. And not to sound vain, but if I can tolerate habaneros, there's no reason why I can't tolerate regular red peppers. I drank 2-3 glasses of water, and that had no effect whatsoever.

Today I woke up with awful throat pain that is getting progressively worse by the hour. I think I am losing my voice. The rest of my body feels fine, so I don't think it's the flu or a throat infection (unless the peppers somehow caused this). More than anything, I'm worried that it was a non-natural substance that screwed my throat up. Has anyone encountered this before? If so, should I go visit a doctor?